A qualitative and quantitative investigation of structural morphology in the neonatal ilium

Cortical and trabecular bone characteristics can be used to make predictions regarding previous loading regimes and developmental milestones which a bone has encountered. This has led to the suggestion that in the adult pelvis, bone patterning is related to the remodeling forces generated during bipedal locomotion. However, during the neonatal period the pelvic complex is non-load bearing, therefore, structural organisation of the ilium cannot reflect direct stance related forces. This study considers the cortical and trabecular bone structure in the ilium of the fetal and newborn infant, a structural configuration which until now has remained largely neglected in the literature. Only recently, with the advent of imaging modalities, has a greater insight and understanding of previously unexplored human bone structural composition and developing bone structure been made possible. In this study, multiple imaging techniques were applied to establish the optimal modality for application to the assessment of bone microstructure. Plain plate macroradiography and micro-computed tomography were identified as the gold standard imaging modalities for bone structural analysis for respective qualitative and quantitative assessment. These techniques were applied to gain a perspective of bone form from a sample of fetal and neonatal ilia selected from the Scheuer collection of juvenile remains. Initially, qualitative analysis highlighted consistent and well-defined patterns of cortical and trabecular bone organisation within the fetal and neonatal ilium, which corresponded with previously recognised regions in the adult that have been attributed directly to forces associated with bipedal locomotion. This was highly unexpected as the early developmental ilium is non-load bearing. Subsequently, quantification of the neonatal cortical and trabecular structure reinforced radiographic observations by identifying regions of significant architectural arrangement. Further investigation of this precocious patterning led to a revised proposal for the mode of growth in the human ilium during the neonatal developmental period. Analysis revealed statistically significant differences in regional trabecular characteristics and cortical thicknesses which have formed the basis of a proposed growth model for the ilium. The presence of ‘progressive growth regions’ and ‘restricted growth regions’ which appear to relate to metaphyseal and non-metaphyseal borders of the ilium have been demonstrated. Analysis of the early iliac bone pattern is important for understanding the relationship between trabecular bone patterning and cortical bone structure during the earliest stages of development in response to the specific functional forces acting during this period. It is suggested that the seemingly organised rudimentary scaffold observed in the early developmental ilium may be attributable to early ossification patterning, non-weight bearing anatomical interactions or even to a predetermined genetic blueprint. It must also be postulated that whilst the observed patterning may be indicative of a predetermined inherent template, early non-load bearing locomotive influences may subsequently be superimposed upon this scaffolding and perhaps reinforced and likely remodelled at a later age. Ultimately, the analysis of this fundamental primary pattern has core implications for understanding the earliest changes in iliac trabecular architecture and provides a baseline insight into future ontogenetic development and bipedal capabilities. Finally, the structural data and statistical analysis presented challenge the current concept of implied centrifugal ossification within the human ilium and present evidence of an alternative pattern of ossification that is largely dictated and controlled by basic anatomical principles.EThOS - Electronic Theses Online ServiceLeng TrustWenner-Gren FoundationBiotechnology and Biological Sciences Research CouncilGBUnited Kingdo

A qualitative and quantitative investigation of structural morphology in the neonatal ilium

Cortical and trabecular bone characteristics can be used to make predictions regarding previous loading regimes and developmental milestones which a bone has encountered. This has led to the suggestion that in the adult pelvis, bone patterning is related to the remodeling forces generated during bipedal locomotion. However, during the neonatal period the pelvic complex is non-load bearing, therefore, structural organisation of the ilium cannot reflect direct stance related forces. This study considers the cortical and trabecular bone structure in the ilium of the fetal and newborn infant, a structural configuration which until now has remained largely neglected in the literature. Only recently, with the advent of imaging modalities, has a greater insight and understanding of previously unexplored human bone structural composition and developing bone structure been made possible. In this study, multiple imaging techniques were applied to establish the optimal modality for application to the assessment of bone microstructure. Plain plate macroradiography and micro-computed tomography were identified as the gold standard imaging modalities for bone structural analysis for respective qualitative and quantitative assessment. These techniques were applied to gain a perspective of bone form from a sample of fetal and neonatal ilia selected from the Scheuer collection of juvenile remains. Initially, qualitative analysis highlighted consistent and well-defined patterns of cortical and trabecular bone organisation within the fetal and neonatal ilium, which corresponded with previously recognised regions in the adult that have been attributed directly to forces associated with bipedal locomotion. This was highly unexpected as the early developmental ilium is non-load bearing. Subsequently, quantification of the neonatal cortical and trabecular structure reinforced radiographic observations by identifying regions of significant architectural arrangement. Further investigation of this precocious patterning led to a revised proposal for the mode of growth in the human ilium during the neonatal developmental period. Analysis revealed statistically significant differences in regional trabecular characteristics and cortical thicknesses which have formed the basis of a proposed growth model for the ilium. The presence of ‘progressive growth regions’ and ‘restricted growth regions’ which appear to relate to metaphyseal and non-metaphyseal borders of the ilium have been demonstrated. Analysis of the early iliac bone pattern is important for understanding the relationship between trabecular bone patterning and cortical bone structure during the earliest stages of development in response to the specific functional forces acting during this period. It is suggested that the seemingly organised rudimentary scaffold observed in the early developmental ilium may be attributable to early ossification patterning, non-weight bearing anatomical interactions or even to a predetermined genetic blueprint. It must also be postulated that whilst the observed patterning may be indicative of a predetermined inherent template, early non-load bearing locomotive influences may subsequently be superimposed upon this scaffolding and perhaps reinforced and likely remodelled at a later age. Ultimately, the analysis of this fundamental primary pattern has core implications for understanding the earliest changes in iliac trabecular architecture and provides a baseline insight into future ontogenetic development and bipedal capabilities. Finally, the structural data and statistical analysis presented challenge the current concept of implied centrifugal ossification within the human ilium and present evidence of an alternative pattern of ossification that is largely dictated and controlled by basic anatomical principles.EThOS - Electronic Theses Online ServiceLeng TrustWenner-Gren FoundationBiotechnology and Biological Sciences Research CouncilGBUnited Kingdo

Familial adenomatous polyposis : new insights into the craniofacial radiograph features

Tese (doutorado) — Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, Programa de Pós-Graduação em Saúde Animal, 2020.A Polipose Adenomatosa Familial (FAP) é uma doença com padrão de herança autossômico dominante predisponente ao câncer colorretal. No Brasil, o câncer colorretal está entre as quatro neoplasias malignas mais frequentes e é o terceiro em mortalidade em ambos os sexos. Os pacientes com FAP, além de apresentarem manifestações intestinais, apresentam alterações dento-ósseas. Dentre essas, são relatados presença de osteomas, odontomas, dentes supranumerários, escleroses ósseas no complexo maxilomandibular que podem se manifestar precocemente - antes do aparecimento dos pólipos intestinais. Uma revisão sistemática da literatura demonstrou a importância da investigação de doenças sistêmicas por meio de alterações ósseas presentes em radiografias panorâmicas - rotineiramente requisitadas por cirurgiões-dentistas. Baseando em artigos incluídos na revisão, regiões de interesse foram mapeadas como pontos de referência para uma futura área de análise de índices radiomorfométricos. Alterações ósseas foram detectadas quando condiçōes sistêmicas acometiam os pacientes. Um segundo projeto demonstrou que o trabeculado ósseo mandibular de pacientes FAP, quando comparados com controles pareados, apresentou alterações micro estruturais no osso trabecular mandibular quando submetidos a análise de dimensão fractal. Numa tentativa de englobar pacientes pediátricos e adultos em países diferentes, um estudo multicêntrico foi elaborado em parceria com a Universidade de Brasília e o Mercy’s Children Hospital nos Estados Unidos. Pacientes pediátricos FAP mostraram alterações ósseas similares aos adultos. Quando esses pacientes foram comparados aos controles, os pacientes FAP apresentaram alterações no padrão trabeculado ósseo, além de alterações dentais. Esse último estudo têm como objetivo recomendar o acompanhamento odontológico periódico através de radiografia panorâmica convencional anual em pacientes FAP e nas famílias em risco. Além de enfatizar a necessidade de participação do dentista nas equipes médicas multiprofissionais que acompanham essas famílias. Assim, esse trabalho alerta e conscientiza de forma crítica, baseada em evidências, nas equipes de saúde bucal sobre a importância de investigar doenças sistêmicas, alterações ósseas e FAP nos exames radiográficos rotineiros.Familial Adenomatous Polyposis (FAP) is an autosomal dominant disorder caused by mutations in the Adenomatous Polyposis Coli gene (APC). Worldwide, colorectal cancer (CRC) is within the third most frequent malignant neoplasm. CRC ranked as the third modality associated-death with females and males. The FAP patients, in addition to present extraintestinal manifestations, also show dento-osseous alterations. These alterations are mostly associated with odontomas, osteomas, supernumerary teeth, and idiopathic osteosclerosis. These last could precede the clinical evidence of intestinal polyps. A systemic review of the literature demonstrated the importance of the systemic disease investigation through mandibular trabecular bone alterations using conventional panoramic radiographs – which are routinely prescribed by dentists in general practice. Based on the articles included in this systematic review, regions of interest were mapped and used as reference-points to investigate radiomorphometric indexes. Besides, trabecular and cortical bone alterations were possibly associated with systemic conditions. A second project demonstrated that the mandibular trabecular bone pattern in FAP patients when compared to healthy individuals, showed texture discrepancies and narrow bone alterations via the fractal dimension analysis. In an attempt to radiographically assess FAP children and adults in different locations, we developed a multicentric study in partnership with the Children’s Mercy Hospital in Kansas City, United States. Pediatric FAP demonstrated osseous alterations that were similar to the adults affected by the same disease. Compared to the healthy controls, the FAP patients, presented alterations in the trabecular bone texture of the mandible. These studies aim to recommend the annual dental follow-up on the FAP patients and families at risk using the panoramic radiograph. In addition to emphasizing the importance of a dentist collaborating in the FAP multispecialty team. Thus, our objective is to alert and create critical thinking, based on scientific evidence, in the dental health teams about the importance of the opportunistic surveillance and screening of systemic diseases and FAP extraintestinal manifestations on the routinely taken dental radiographs